The Central London site had logistical access restrictions limiting the delivery of plant and materials. This was further exacerbated by an existing façade requiring 600mm diameter piled support, in only 3.8m of headroom. Behind the façade the scheme required a 900mm diameter secant wall at different platform levels, bearing piles at (1800mm and 55m deep), and large diameter plunge columns to be installed with an installation tolerance of 1 in 400.

The Martello Solution

Martello successfully delivered the 14 no, 600mm diameter façade retention piles to 25m deep, using their MP4002 piling rig, installing up to 10m of temporary casing, in just 3.8m of headroom. This work was undertaken before the internal floors were removed thanks to Martello’s ability to work in 3.8m of headroom, allowing the contractor to progress with the further demolition of the existing structure, thereby releasing the rest of the site.
Behind the façade, the scheme proposal of a 900mm secant wall, was successfully re-designed by Martello as a 750mm wall, furnishing the client with additional floor space, and cost and programme savings.

Specific Project Features

The project is a part top down construction for a triple basement structure, requiring a perimeter secant wall, along with plunge columns, to assist the scheme for the wall support, and also to provide support for the upper woks.

The wall piles, 1.8m diameter bearing piles and plunge columns are installed with a Delmag RH 28 piling rig.
This rig provides delivery of all aspects of the scheme including the 55m deep tension piles.
The plunge columns are installed and positioned using Martello’s in-house designed plunge column frame.

Future Potential

With this project Martello were able to demonstrate their integrated approach to the resolution of a client’s problems, by providing innovative design, and the correct expertise and equipment to each particular environment.